The present invention relates to a drive apparatus which is operable to move control surfaces on wings of an aircraft.
Known apparatus for effecting movement of control surfaces, such as slats and/or flaps, on the wings of an aircraft, have utilized torque limiter/brakes for the control surface or surfaces on the left wing of the aircraft and another torque limiter/brake for the control surfaces on the right wing of the aircraft. Each of these torque limiter/brakes has been coupled to a central power control unit with a long coupling shaft.
With previous devices which effect movement of control surfaces on the wings of an aircraft, the long coupling shaft is required to absorb the shock load generated from the kinetic energy of the drive train during a sudden torque limiter/brake engagement. This sudden engagement could be caused by a jammed output shaft.
During sudden torque limiter/brake engagement, the driving devices for the long coupling shafts may be damaged due to sudden shock loading. This sudden shock loading may result from the inertia of motors and/or other components of the drive apparatus.
A drive apparatus constructed in accordance with the present invention is operable to move a first control surface on a first wing of an aircraft and a second control surface on a second wing of the aircraft. The drive apparatus may be connected to the control surfaces by drive shafts. The drive apparatus is operable to interrupt rotation of drive shafts in response to the transmission of torque of a predetermined magnitude.
When the drive apparatus interrupts rotation of the drive shafts, the drive apparatus is effective to absorb kinetic energy in order to limit shock loading on the components of the drive apparatus. The drive apparatus may include a first brake assembly which is connected with a control surface on one wing of the aircraft. In the event of a malfunctioning of the control surface, such as a jamming of the control surface or a drive mechanism connected directly to the control surface, the first brake assembly is operable to an engaged condition to prevent rotation of a drive shaft connected with the first control surface. Similarly, the drive apparatus may include a second brake assembly which is connected with a control surface on a second wing of the aircraft. In the event of a malfunctioning of the control surface on the second wing of the aircraft, the second brake assembly is operable to an engaged condition to prevent rotation of a drive shaft connected with the second control surface.
One or more shock absorbing assemblies may be provided to absorb kinetic energy of components of the drive apparatus upon engagement of the brake assemblies to interrupt rotation of the control surface drive shafts. The shock absorbing assembly or assemblies slip when a predetermined torque is transmitted. The predetermined torque at which a shock absorbing assembly begins to slip is at least as great as the sum of the torques required to effect operation of the torque limiting brake assemblies to their engaged condition.